TC4钛合金薄壁带筋锥形环辗轧充填规律

钛合金薄壁带筋锥形环件是航空航天关键基础构件,型槽充填不满、截面轮廓难以精确成形,是该复杂异形环件精密辗轧成形面临的瓶颈问题。本文分析了影响型槽充填行为的关键影响因素,即决定塑性变形行为的每转进给量、以及决定每转进给量在环件内外表面分配比例的驱动辊半径和芯辊半径;以某TC4钛合金薄壁带外筋锥形环辗轧为研究对象,通过ABAQUS的VUAMP子程序开发,建立了实现以常每转进给量进给的芯辊运动闭环控制有限元仿真模型;进而模拟揭示了每转进给量、驱动辊半径和芯辊半径对型槽充填质量(充填率、型槽入口变形及其均匀性)的影响规律。结果表明:随着每转进给量增大,充填率先增大后减小,表明存在一个最佳的每转进给量最利于充填;随着每转进给量增大,型槽入口区域变形越小且分布越均匀,可有效抑制该区域产生裂纹缺陷;随着驱动辊半径增大,充填率逐渐减小,不利于型槽充填;随着芯辊半径增大,充填率逐渐增大,有利于型槽充填。     

Development of a super-pressure balloon with a diamond-shaped net

The essential reason of the lobed-pumpkin shaped super-pressure balloon to withstand against the high pressure is that the local curvature of the balloon film is kept small. Recently, it has been found that the small local curvature can also be obtained if the balloon is covered by a diamond-shaped net with a vertically elongated shape. The development of the super-pressure balloon using this method was started from a 3-m balloon with a polyethylene film covered by a net using Kevlar ropes. The ground inflation test showed the expected high burst pressure. Then, a 6-m and a 12-m balloon using a polyethylene film and a net using the Vectran were developed and stable deployment was checked through the ground inflation tests. The flight test of a 3000 m³ balloon was performed in 2013 and shown to resist a pressure of at least 400 Pa. In the future, after testing a new design to relax a possible stress concentration around the polar area, test flights of scaled balloons will be performed gradually enlarging their size. The goal is to launch a 300,000 m³ super-pressure balloon.     

The influence of interplanetary shocks on solar protons measured in the stratosphere.

Since the beginning of the 22nd solar cycle twenty solar proton events were observed by the regular balloon measurements of cosmic rays. Temporal changes of intensities and energy spectra of solar protons with energy 100-500 MeV were obtained. The strong influence of interplanetary shock waves on the proton flux characteristics near the Earth was observed. Possible effects of solar proton transport in the vicinity of shock fronts are discussed to explain the observational data.     

Stratospheric measurements of cosmic rays in the 19th-22nd solar activity cycles.

Balloon measurements of cosmic rays were made practically every day at several locations of the former USSR and in Antarctica over a period of more than 30 years. These measurements provide a means for assessment and control of ionizing radiation at the altitudes from ground level up to 30-35 km.     

8"×8" full color cockpit display

The operation of active matrix liquid crystal displays (AMLCDs), the preferred flat-panel displays for avionic and aerospace applications, is explained. An 8-in.×8-in. full-color AMLCD designed for a military aircraft is described, as well as the principles of the p-i-n diode switch on which its design is based. The performance characteristics of the display are examined     

Some results of the effect of space flight factors on Drosophila melanogaster.

Two experiments with Drosophila melanogaster males were performed aboard the Salyut 6 orbital station. Mutagenic effects of a 8 day space flight on sex chromosome nondisjunction and intergene recombination in chromosome II were studied. The space flight factors (SFF) increased the frequency of chromosome nondisjunction and recombination. The model experiments showed that the combined effects of vibration and acceleration do not cover the whole spectrum of space flight mutagenic factors. These data suggest that heavy space ions are mainly responsible for the observed effect.     

Biological investigations aboard biosatellite Cosmos-782

The Cosmos-782 flight from 25 November to 15 December 1975, carried biological experiments designed to study the effects of weightlessness on insects and fish and on gravitropism and growth in several seed varieties. Investigations carried out on Drosophila melanogaster measured the frequency of recessive lethal mutations and the change in genetic distances in the sex chromosome. The study of Fundulus heteroclitus eggs and fry compared the effects of weightlessness and artificial gravity. Plants experiments studied spatial orientation of over and underground organs of Pinus silvestris and Crepis capillaris seeds. Other investigations used Phycomyces blakesleanus to compare spatial orientation and growth and development in weightlessness and artificial gravity.     

Orthogonalization Techniques of a Direction Cosine Matrix

Three orthogonalization techniques to correct errors in the computeddirection cosine matrix are introduced. One of these techniques is avectorial technique based on the fact that the three rows of a directioncosine matrix constitute an orthonormal set of vectors in aree-threedimensional space. The other two iterative techniques are based onthe fact that the inverse and transpose of an orthogonal matrix areequal. In computing a time-varying direction cosine matrix computationalional errors are accompanied by the loss of the orthogonaliterty prop-rty of the matrix. When one of these three techniques is useo re-restore the orthogonality of the matrix, the computational errors arealso corrected. These techniques were tested experimentally and theresults, given in this paper, were compared with a method used by the Honeywell Corporation.     

Temporal analysis of suspended solid in Tokyo Bay by Landsat data

The amount of suspended solid (S.S.) discharged from Tokyo metropolitan area is estimated by use of multi-temporal Landsat data from 1979 to 1980. The method to estimate S.S. was verified with sea truth data which was observed with Landsat passes covering Tokyo Bay. The radiometric information is normalized against seasonal change of sun illuminations and atmospheric conditions. Path radiance estimation methods were discussed, because its effects are very sensitive to the estimation of S.S. concentration by Landsat MSS data. Temporal changes of S.S. distribution was also interpreted.